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Raju Rangoju 8e4d3d8a5e
spi: spi-mem: Add fix to avoid divide error
For some SPI flash memory operations, dummy bytes are not mandatory. For
example, in Winbond SPINAND flash memory devices, the `write_cache` and
`update_cache` operation variants have zero dummy bytes. Calculating the
duration for SPI memory operations with zero dummy bytes causes
a divide error when `ncycles` is calculated in the
spi_mem_calc_op_duration().

Add changes to skip the 'ncylcles' calculation for zero dummy bytes.

Following divide error is fixed by this change:

 Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI
...

  ? do_trap+0xdb/0x100
  ? do_error_trap+0x75/0xb0
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? exc_divide_error+0x3b/0x70
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? asm_exc_divide_error+0x1b/0x20
  ? spi_mem_calc_op_duration+0x56/0xb0
  ? spinand_select_op_variant+0xee/0x190 [spinand]
  spinand_match_and_init+0x13e/0x1a0 [spinand]
  spinand_manufacturer_match+0x6e/0xa0 [spinand]
  spinand_probe+0x357/0x7f0 [spinand]
  ? kernfs_activate+0x87/0xd0
  spi_mem_probe+0x7a/0xb0
  spi_probe+0x7d/0x130

Fixes: 226d6cb3cb ("spi: spi-mem: Estimate the time taken by operations")
Suggested-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://patch.msgid.link/20250424121333.417372-1-Raju.Rangoju@amd.com
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2025-04-25 13:19:56 +01:00
arch bpf-fixes 2025-04-12 12:48:10 -07:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation A few more miscellaneous ext4 bug fixes and cleanups including some 2025-04-13 07:15:50 -07:00
drivers spi: spi-mem: Add fix to avoid divide error 2025-04-25 13:19:56 +01:00
fs Changes since last update: 2025-04-13 10:52:04 -07:00
include drm fixes for 6.15-rc2 2025-04-10 20:30:06 -07:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring/kbuf: reject zero sized provided buffers 2025-04-07 07:51:23 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel tracing fixes for v6.15 2025-04-12 15:37:40 -07:00
lib CRC cleanups for 6.15 2025-04-08 12:09:28 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
net bpf-fixes 2025-04-12 12:48:10 -07:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
scripts Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
security mseal sysmap: kernel config and header change 2025-04-01 15:17:14 -07:00
sound soundwire fix for 6.15-rc1 2025-04-06 12:04:53 -07:00
tools memblock: fix build of memblock test 2025-04-13 07:11:33 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-04-08 13:47:55 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap mailmap: add an entry for Nicolas Schier 2025-04-01 15:20:45 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: add more keywords for the GPIO subsystem entry 2025-04-08 10:41:58 +02:00
Makefile Linux 6.15-rc2 2025-04-13 11:54:49 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.